Red dye study of Piscataqua River examines shellfish harvesting

NEWINGTON — The wind was whipping off the Piscataqua River Tuesday while three boats and their crews worked in frigid temperatures, using red dye to undertake the first shellfish harvesting study of the lower Piscataqua River.

NEWINGTON — The wind was whipping off the Piscataqua River Tuesday while three boats and their crews worked in frigid temperatures, using red dye to undertake the first shellfish harvesting study of the lower Piscataqua River.

“I'm not going to lie. It's been cold out there,” said Chis Nash of the N.H. Department of Environmental Services while at Great Bay Marine.

Nash and other state and federal workers had been out since dawn, working to gather data on the pattern of dispersal into the river from the outflow at the Portsmouth Wastewater Treatment Facility on Peirce Island.

The goal is to determine whether any parts of the lower Piscataqua River can be opened to commercial shellfish farming, or whether clam flats can be opened.

Boats, equipment and personnel from the Food and Drug Administration and the Environmental Protection Agency are helping N.H. DES and the Maine Department of Marine Resources gather the data.

Two of the boats were equipped with fluorometers, machines that measure the level of a fluorescent red dye that was placed in the outflow starting at 1 a.m. Tuesday morning.

The nontoxic dye was dispersed on the tide over the entire lower Piscataqua River area as well as out into the mouth of the river.

In addition to the fluorometers that crews dragged behind the boats as they traversed the river, 16 additional instruments were placed strategically in the river itself.

The study is expected to last throughout the week, but Tuesday was the crucial day.

“The first day is important,” said Nash, as tides and wave action will disperse the dye significantly as the days progress.

Nash said the FDA has been crucial in the study, because it has the fluorometers and the experts who know how to read the instruments. An FDA official sat on the boats periodically downloading information onto a laptop.

Nash said the study is the first of its kind on the lower Piscataqua, although the dispersal patterns from other wastewater treatment facilities along the river and into the Great Bay have been similarly tested.

There has been interest in both a commercial oyster and blue mussel farm operation on the New Hampshire side of the river. In Maine, interest in opening recreational clam flats has been shown by the towns of Kittery and Eliot.

Nash said he's found traces of the dye in the area near Great Bay Marine, upriver from the wastwater treatment plant.

Nash declined to say how long it will take him to complete the analysis of the data that's being collected.